1. Field of the Invention
The present invention relates to a plastic container for contents such as foodstuff and medicines. More particularly, the present invention pertains to a method for inspecting the sealing property of a plastic container and a plastic container inspected by the method.
2. Discussion of the Prior Art
As a container for charging foodstuff or medicines, a metal container such as a metal can, a glass bottle and a plastic container are generally used. These containers are also subjected to a retort sterilization process after the contents are charged into the container. Developments have been made to provide a method for inspecting the sealing-.property of the container which is charged with the contents, the method being appropriate for the property of the container. For example, the plastic container suitable for the retort sterilization includes a retort pouch and in this type of container a visual inspection is carried out by depressing the pouch and detecting leakage. As an alternative method, a proposal is made to put the container in a chamber of a reduced pressure and detect a pressure change in the chamber which may be produced due to a leakage. It should however be noted that the aforementioned methods which have hithertofore been developed for the inspection of the sealing property of a plastic container are low in detecting precision so that they are not widely used in actual practice. Further, no practical method has as yet been developed for the inspection of the sealing property of a plastic container of a bottle configuration, cup configuration or a tray configuration.